dvi -> hdmi full hd not working correctly

[lenselijer]

I bought a dvi > hdmi cable to connect my air to the hdmi port of a samsung 46inch tv.

The picture is perfect at 1600x1200, but when i select 1920x1080 it looks really bad, sorta like 16bit colors.

When I use a vga cable it looks fine at 1920x1080.
So what am i doing wrong?
or has it something to do with the dvi > hdmi cable i bought?

 

[robotica]

most HD TV's ive used take different resolutions through HDMI and VGA
bit strange but check with your TV manual